100-400 4.5-5.6 troubleshooting, paper between lens layers?

[John_Arneson]

Anyone seen this before? Still seems to shoot fine even around what appears to be paper between the lens layers... unfortunately discovered on vacation/photo shoot 😉  Any idea how problematic it will be to repair ($-$$$)...

[MikeSowsun · Accepted solution]

Canon actually uses pieces of black tape inside many of their lenses. My guess is a piece of tape has come loose and found it’s way to the front of the lens. 

[John_Arneson]

Thanks for all the feedback! Mike the images you shared look similar, and the explanation makes sense 👌

This is the old IS version, bought it used 5 years ago for about 700 and it’s worked wonderfully. The autofocus is just not functioning properly now. Planning to send in to Canon for a repair estimate, if possible to just remove the tape they’ll likely give it a go. It’s not supported anymore so if other parts are needed I’ll likely have to move on.  

Will post an update in a few weeks. 

[jrhoffman75]

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@John_Arneson wrote:

Thanks for all the feedback! Mike the images you shared look similar, and the explanation makes sense 👌

This is the old IS version, bought it used 5 years ago for about 700 and it’s worked wonderfully. The autofocus is just not functioning properly now. Planning to send in to Canon for a repair estimate, if possible to just remove the tape they’ll likely give it a go. It’s not supported anymore so if other parts are needed I’ll likely have to move on.  

Will post an update in a few weeks. 

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Please let us know what Canon says, including if they say they won't work on it at all. I have read elsewhere that once they run out of parts they won't work on a device because if they inadvertently damage something they won't be able to repair it.

[shadowsports]

+1 on that John.  midwestcamera dot com is another alternative given the age of the lens.

[ebiggs1]

"... I have read elsewhere that once they run out of parts they won't work on a device because if they inadvertently damage something they won't be able to repair it."

Its not just that which is probably a minor factor but Canon goes over the entire camera or lens before they return it. If there is any other part they don't have and they replace it they cannot guarantee the lens. 

[John_Arneson · Accepted solution]

Hey all, in followup it turns out it was the backing to the flex circuit and thankfully Mike at PhotoTronic in Topeka was able to fix and ship back under $200, top notch work 😃

Canon would not accept for return, offered a tiny discount on trade in for a newer model.